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'the use of whichwill behercinafter set forth.

CHARLIE-s A. sMfi'rn, or NEW YORK, N. Y.

Letters Patent No. 81,424, dated .August 25, 1868.

IMPROVEMENT IN LIFTINGJAGK.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, CHARLES A. SMITH, of New York, in the county of New York, and State of New York, have invented certain new and useful Improvements in Lifting-Jacks; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part ot' this specication, and which represents a sectional elevation of thersame,

The nature of my invention consists in the general arrangement of a lifting-jack, by'the use of which bodies of any weight may be raised with perfect ease. v A` i Andiu' order to enable othersskilled in the art to which my invention appertainsv to make and use the same, I will now" proceed todescribe its construction and operation.

A represents a box or casingof suitable material, and of any dimensions required, one side of which is grooved. e

In this groove a slide, B, moves up and down, and a slot in the upper end of said casing allows it to extend above the same when raised.

v 'lo the inner side of this slide B is firmly secured a 'ratch-bar, C, or the slide and xjatch-bar may be made or cast solid in one piece if so desired. i

Near the upper part of the casing A, a shaft', a, passes through the same, which shaft hasV itsobearingsin' y the front and rear sides of said easing. i

On the shaft a, three wheels are -rmly secured: one, a ratchet-wheel, D, which is placed near or against the rear side of the casing, and between said rear side and the slide B; one, a cog-wheel, E, which gears into the cogs oi' the ratch-bar C; andthe third a safety-wheel, F, between the slide B and the front side of the casing,

0n each sid'e ofthe ratchet-wheel D an arm, G, is placed on the shaft a, which arms extend through a slot in the side ofthe casing.

Bctweenand to these -arms a lever, II, is firmly secured. A pawl, I, is also pivoted between said arms, which pawl extends through the slot already mentioned in the. side ot` the casing, above the ratchet-wheel D, :tn/d its inner end being provided with a hook, as shown, it catches the teeth of saidA wheel, so that by moving the lever H downwards, the ratchet-wheel D istnrned, and as, at the same time, the cog-wheel Eis revolving,

the slide vB Wiil be raised above the casingaA.

Aspring, b, secured'to the end of the lever H, presses the hooked pawl I in the teeth of the ratch-wheel, and when the lever is raised again, said spring gives enough to allow the pawl to glide over the teeth, catching into another when the lever .is again lowered.

In the rear side ofthe casing, another pawl', K, is pivoted, which is of the same construction as the pawl I, and which is also pressed in the teeth ot the ratchet-wheel D, by a spring, d, thus preventing the said wheel from turning backwards when the downward pressure on the lever II is removed.

The additional wheel F is used when the weight is so heavy that the slide B would move down, although the pawl I catches the teeth of the ratchet-wheel. For this purpose aV spring-band, z', is passed around said Awheel and secured to a. handle, L, in sucha manner that, by pressing down on said handle, the wheel F is preslide B np in the desired position.

vented from revolving, and, et course, thereby preventing the cog-wheel E from giving way, and holding thc Having thus fully described my invention, what I claim as new, and desire to secure by Letterslatent, islhe combination' of the lover 1I, ratchet-wheel D, cogged wheel E, slide B, ratch-bar C, with the safetywheel F, and 'brake or safety-band z', ali constructed as described, and operating substantially as and for the 'purposes herein set forth,

In testimony lthat Ielaim thc foregoing as my own, I aix my signature in presence of two witnesses.

' CHARLES A. SMITH.

Witnesses:

Z. C. SMITH, Josnrn H. CLARK. 

